attack-tree.md

Attack Tree Analysis for cucumber/cucumber-ruby

Objective: RCE or Data Exfiltration via Cucumber-Ruby

Attack Tree Visualization

                                      +-------------------------------------------------+
                                      |  Attacker Goal: RCE or Data Exfiltration via    |
                                      |                 Cucumber-Ruby                   |
                                      +-------------------------------------------------+
                                                       |
          +------------------------------------------------------------------------------------------------+
          |                                                                                                |
+---------------------+                                                                    +---------------------+
|  **1. Malicious Step**|                                                                    | 3. Dependency       |
|     **Definitions**   |                                                                    |     Vulnerabilities |
|     [HIGH-RISK]      |                                                                    |                     |
+---------------------+                                                                    +---------------------+
          |                                                                                                |
+---------+---------+                                                                    +---------+
| 1.a.    | 1.b.    |                                                                    | 3.b.    |
| **Execute** | **Execute** |                                                                    | Exploit |
| **System**  | **Ruby**    |                                                                    | Unknown |
| **Command** | **Code**    |                                                                    | (0-day) |
| **(Shell)** |         |                                                                    | in Dep. |
| [CRITICAL]| [CRITICAL]|                                                                    | [CRITICAL]|
+---------+---------+                                                                    +---------+
          |
+---------+
| 1.c.    |
| Read    |
| Files   |
| [CRITICAL]|
+---------+

Attack Tree Path: [HIGH-RISK PATH]: 1 -> 1.a

• 1. Malicious Step Definitions [HIGH-RISK]

  • Description: This is the primary and most direct attack vector. Cucumber-Ruby executes Ruby code defined in step definitions. If an attacker can inject or modify these step definitions, they can achieve a variety of malicious goals, including RCE and data exfiltration. The attacker needs to find a way to introduce their code into the step definitions, which could be through various means like exploiting a vulnerability in the CI/CD pipeline, compromising a developer's account, or finding a flaw in a web interface used to manage tests.

  • Sub-Vectors (Critical Nodes):

    • 1.a. Execute System Command (Shell) [CRITICAL]
      • Description: The most direct path to Remote Code Execution (RCE). The attacker crafts a step definition that uses Ruby methods like backticks (`), system(), exec(), or Open3.capture3 to execute arbitrary shell commands on the target system.
      • Example:

        Given('I run a malicious command') do
          `rm -rf /` # Extremely dangerous! Illustrative only.
        end

      • Mitigation: Strictly control and review step definitions. Never allow user input to directly influence shell commands. Sanitize any user-provided data used within step definitions. Avoid using these dangerous functions with any untrusted input.

Attack Tree Path: [HIGH-RISK PATH]: 1 -> 1.b

• 1. Malicious Step Definitions [HIGH-RISK]

  • Description: This is the primary and most direct attack vector. Cucumber-Ruby executes Ruby code defined in step definitions. If an attacker can inject or modify these step definitions, they can achieve a variety of malicious goals, including RCE and data exfiltration. The attacker needs to find a way to introduce their code into the step definitions, which could be through various means like exploiting a vulnerability in the CI/CD pipeline, compromising a developer's account, or finding a flaw in a web interface used to manage tests.

  • Sub-Vectors (Critical Nodes):

    • 1.b. Execute Ruby Code [CRITICAL]
      • Description: Allows for RCE through the execution of arbitrary Ruby code. Attackers might use eval(), instance_eval(), or manipulate metaprogramming features.
      • Example:

        Given(/^I execute arbitrary Ruby code: (.*)$/) do |code|
          eval(code) # Extremely dangerous! Illustrative only.
        end

      • Mitigation: Similar to 1.a, strictly control step definitions and avoid using eval() or similar functions with untrusted input. Thorough code reviews are essential.

Attack Tree Path: [HIGH-RISK PATH]: 1 -> 1.c

• 1. Malicious Step Definitions [HIGH-RISK]

  • Description: This is the primary and most direct attack vector. Cucumber-Ruby executes Ruby code defined in step definitions. If an attacker can inject or modify these step definitions, they can achieve a variety of malicious goals, including RCE and data exfiltration. The attacker needs to find a way to introduce their code into the step definitions, which could be through various means like exploiting a vulnerability in the CI/CD pipeline, compromising a developer's account, or finding a flaw in a web interface used to manage tests.

  • Sub-Vectors (Critical Nodes):

    • 1.c. Read Files [CRITICAL]
      • Description: Allows the attacker to read arbitrary files from the system, potentially exposing sensitive data like configuration files, database credentials, or source code.
      • Example:

        Given('I read the contents of {string}') do |file_path|
          puts File.read(file_path)
        end

      • Mitigation: Sanitize any user input used to specify file paths. Use whitelisting to restrict access to only specific, necessary files. Run Cucumber tests with the least necessary privileges.

Attack Tree Path: [HIGH-RISK PATH]: 3 -> 3.b (Although very low likelihood, the impact is critical)

• 3. Dependency Vulnerabilities

  • Description: Cucumber-Ruby, like any software, relies on external libraries (dependencies). Vulnerabilities in these dependencies can be exploited to compromise the application.

  • Sub-Vectors (Critical Nodes):

    • 3.b. Exploit Unknown (0-day) in Dependency [CRITICAL]
      • Description: A zero-day vulnerability is a previously unknown flaw in software. Exploiting a 0-day in a Cucumber-Ruby dependency could lead to RCE or other severe consequences. This is a very low likelihood but very high impact scenario.
      • Mitigation: While you cannot directly prevent 0-days, you can minimize their impact. Employ defense-in-depth strategies:
        • Principle of Least Privilege: Run tests with minimal permissions.
        • Containerization: Isolate the test environment (e.g., using Docker).
        • Robust Logging and Monitoring: Detect unusual activity.
        • Regular Security Audits: Help identify potential weaknesses.
        • Rapid Response Plan: Have a plan in place to quickly patch and mitigate vulnerabilities when they are disclosed.